There is a growing demand for exercise machines to become more entertaining and less tedious. Similarly, users of virtual reality computer games wish to enhance their experience through physical stimulation and exertion, thereby increasing their “immersion” in the game. To this end many developments have sought to improve the computer gaming experience, for instance through three-dimensional visual graphics,' surround sound' audio and various devices that provide a physical feedback.
As many games require the player to walk or run around a virtual world several inventions have attempted to simulate walking and running. The key challenge to accomplishing this is to achieve a means of multi-directional movement within the restricted space usually required of such a game, while keeping the whole device compact.
A feature of walking/running exercise devices is that they tend to be computer controlled as opposed to providing an input to a computer. For instance a treadmill requires the user to input the desired speed it should operate at. There are dangers associated with forcing a user to ‘keep up’ with a machine and they may suffer comfort and modesty issues due to the jogging motion. Another feature of many existing devices is that it can be difficult or even impossible to change direction. Ideally a locomotion platform should allow a user to traverse freely in any horizontal direction for any amount of time.
Phillips' U.S. Pat. No. 6,106,397 demonstrates that when a user is constrained to a limited platform area while performing a walk action their movements can be monitored and the data used as input to a computer program.